Mercury Mariner 30/40 4-Stroke Outboard Service Manual 1998, Page 353Get this manual
MANUAL TILT ASSIST
8Inspect check valve for debris; clean debris from check valve if foundIf debris cannot be cleaned from check valvereplace shock piston as an assembly9Clean shock and components with compressed air10Remove inner O-ring
aShock PistonO-ring 11Remove cylinder end cap assembly from shock rod12Inspect shockIf wiper (located in cap) has failed to keep rod clean, replace wiper13Place end cap on clean work surface14Remove rod wiper, inner o-ringand outer o-ringaRod WiperInner O-ringOuter O-ring